Grok 4 Fast Non-Reasoning is a specialized variant of xAI's Grok 4 model optimized for ultra-high context capacity and rapid text-to-text tasks without advanced reasoning capabilities. It focuses on handling extremely long contexts up to 2,000,000 tokens efficiently, delivering fast, deterministic outputs suitable for high-throughput applications.
Grok 4 Fast Non-Reasoning is specifically optimized to handle extremely large context windows up to 2 million tokens, enabling it to process vast amounts of text without losing coherence. While it does not support advanced multi-step reasoning or tool integration, it delivers highly efficient and stable performance in text-to-text generation tasks where context retention over long sequences is critical. Its architecture prioritizes speed and throughput, allowing for rapid response times even with very large inputs. This makes it ideal for applications such as long document summarization, extensive conversational histories, and batch processing where reasoning complexity is not required. The model’s deterministic output further ensures consistent and reliable behavior across repeated requests.
vs. Grok 4: Grok 4 Fast Non-Reasoning trades advanced multi-step reasoning and tool integration for vastly expanded context capacity and faster throughput, making it suitable for applications where reasoning is not critical but context scale is.
vs. GPT-4o: Grok 4 Fast Non-Reasoning surpasses GPT-4o in maximum context length by nearly an order of magnitude, though it lacks multimodal and reasoning features available in GPT-4o.
vs. Grok 4 Fast Reasoning: Grok 4 Fast Non-Reasoning offers higher speed and larger context but omits complex reasoning capabilities present in reasoning-enabled variants.
Measured on the AI/ML API gateway across live traffic. Figures are medians unless stated. Last updated 2026-10-12.
import requests r = requests.post( "https://api.aimlapi.com/v1/chat/completions", headers={"Authorization": "Bearer " + AIMLAPI_KEY}, json={ "model": "x-ai/grok-4-fast-non-reasoning", "messages": [ { "role": "user", "content": "Hello!" } ] }, ) print(r.json())
const r = await fetch("https://api.aimlapi.com/v1/chat/completions", { method: "POST", headers: { Authorization: `Bearer ${process.env.AIMLAPI_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ "model": "x-ai/grok-4-fast-non-reasoning", "messages": [ { "role": "user", "content": "Hello!" } ] }), }); console.log(await r.json());
curl -X POST https://api.aimlapi.com/v1/chat/completions \ -H "Authorization: Bearer $AIMLAPI_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"x-ai/grok-4-fast-non-reasoning","messages":[{"role":"user","content":"Hello!"}]}'
OpenAI-compatible — swap the base URL and it works with your existing SDK.
| Type | Price |
|---|---|
| Input | |
| Output | |
| Cached input |
| Benchmark | Score | What it measures | Source | Retrieved |
|---|---|---|---|---|
| Intelligence | 17.9 | Composite score across standardised reasoning, knowledge and problem-solving evaluations, measured independently by Artificial Analysis | Source | September 12, 2026 |
| Math | 89.7 | Composite score across standardised mathematics evaluations, measured independently by Artificial Analysis | Source | September 12, 2026 |
| Model | Input | Output | Context | Best for |
|---|---|---|---|---|
Grok 4 Fast Non-Reasoning This page | Coding + agents | |||
| Reasoning + agents | ||||
| Balanced coding + agents | ||||
| Long-context, multimodal & agentic workflows | ||||
| Reasoning + agents |
Grok 4 Fast Non-Reasoning has a 2,000,000 tokens context window and can return up to 1,999,000 tokens.
Grok 4 Fast Non-Reasoning takes image, text as input and returns text.
Use x-ai/grok-4-fast-non-reasoning as the model id. Requests go to https://api.aimlapi.com/v1/chat/completions.
Grok 4 Fast Non-Reasoning is priced at input $1.625 / 1M tokens, output $3.25 / 1M tokens, cached input $0.26 / 1M tokens.
Yes, Grok 4 Fast Non-Reasoning can stream responses as they are generated.
Yes, Grok 4 Fast Non-Reasoning accepts image input alongside text.
Grok 4 Fast Non-Reasoning was built by xAI .
It is built to give faster responses with lower latency by skipping the reasoning step.
Yes, it supports function calling, parallel tool calls, and tool use, though it does not perform extended reasoning.
